Antibacterial Activity of the Lactoperoxidase System Combined with Edible Laminaria Hot-Water Extract as a Source of Halide Ions

Hot-water extracts prepared from nine out of 12 samples of dried edible Laminaria reduced the viable numbers of Aggregatibacter actinomycetemcomitans, Staphylococcus aureus, and Esherichia coli below the detection limit after incubation for 5 min when combined with lactoperoxidase, glucose oxidase, and glucose. Some extracts showed higher bactericidal activity and a higher OI^? concentration in the assay mixture after ultrafiltration.     

Blood glucose in marine penaeid prawns: I. Neuroendocrine regulation in Parapenaeopsis hardwickii (Miers). (Crustacea,Decapoda, Penaeidae)

In the present investigation on femaleP. hardwickii, the blood glucose level in bilateral eyestalk extirpated, reinjected with ES extract as well as normal prawns, administered with ES, different concentrations of BR and ThG extracts, was estimated quantitatively after fifteen minutes and two hours. During all treatments there was an immediate hike in blood glucose level after fifteen minutes but after 24 hr. of eyestalk ablation the level does not differ significantly (P > 0.05) from controls. There was a significant (P < 0.01) enhancement in blood glucose level in the cauterized eyestalkless and normal prawns injected with ES extract after 2 hr. There was a considerable (93% level of confidence) decrease in blood glucose level of normal prawns after injecting higher concentrations of BR and ThG extracts. There was an obvious change in blood glucose level due to the endocrine hormones injected from other prawns of the related family. ES extracts ofP. stylifera produced a significant (P < 0.01) increase, whereas higher concentration of BR and ThG extracts caused considerable (92% level of confidence) decrease in blood glucose level after injecting in cauterized eyestalkless prawns. The extracts of the same endocrine centres fromMetapenaeus monocerus did not induce any significant (P > 0.05) alteration in blood glucose quantity ofP. hardwickii. Hence from the above findings it may be inferred that, the hormones produced by eyestalks (X organ-Sinus gland Complex) posses a hyperglycemic factor, whereas hormones released from BR and ThG might be having a property to cause hypoglycemia (?).     

The Biosynthesis of Sucrose and Nucleoside Diphosphate Glucoses in Phaseolus aureus

Sucrose-phosphate synthetase is detectable only in intact chloroplast preparations of Phaseolus aureus. In contrast, sucrose synthetase and uridine diphosphate glucose (UDP-glucose) pyrophosphorylase activities are low in extracts of photosynthetic tissues of P. aureus but are high in extracts of nonphotosynthetic tissues. Activities for ADP-, dTDP-, CDP-, and GDP-glucose pyrophosphorylases are generally higher in extracts of photosynthetic tissues of P. aureus than in extracts of nonphotosynthetic tissues. The high levels of sucrose synthetase and of UDP-glucose pyrophosphorylase found in dark-grown hypocotyls begin to decline about 4 hours after exposure to light at a rate of 50% every 3 hours.     

Hypoglycemic and hypolipidemic effects of alcoholic extract of Tribulus alatus in streptozotocin-induced diabetic rats: a comparative study with T. terrestris (Caltrop)

The extracts of both T. alatus and T. terrestris significantly decrease fasting glucose level in diabetic rats. After 4 and 6 hr, T. alatus extract showed significant reduction in glucose level as compared to T. terrestris. After 3 weeks of treatment with T. alatus extract, glucose level was significantly decreased to the normal level. Both the extracts also caused a significant decrease in the levels of glycosylated hemoglobin, total cholesterol, triglycerides and LDL-cholesterol. The percent of reduction in rats treated with T. alatus extract was significantly higher than that of the rats treated with T. terrestris. The results indicate that alcoholic extract of T. alatus possesses hypoglycemic activity in type-1 model of diabetes.     

Tulipa gesneriana bulb extracts activate promutagenic 7,12-dimethylbenz[a]anthracene in the salmonella/ames assay

Crude extracts from Tulipa gesneriana bulbs have been tested for their ability to activate 7,12-dimethylbenz[a]anthracene (DMBA) in the Salmonella mutagenicity assay. Bacteria of strain TA98 were incubated for 30 min at 37 degrees C with the mixture of the promutagen and bulb extracts prior to plating. The frequency of his+ revertants increased in relation to both the promutagenic dose and the amount of bulb extract in the mixture, and under optimal conditions, was more than 50 times higher than the value found after the action of the promutagen alone. Addition of NADP and glucose 6-phosphate to the incubation mixture did not seem to be obligatory.     

Changes in the activity of glyoxylate cycle enzymes of yeast during hydrocarbon nutrition]

Six strains of Candida guillermondii of different productivity showed a higher isocitrate lyase and malate dehydrogenase activity of cell-free extracts when grown on paraffin than when grown on glucose. In most cases isocitrate dehydrogenase activity was higher on glucose than on paraffin. A positive correlation between isocitrate activity and growth rate was found from studies of the strains of varying growth rate and the cultures cultivated under different conditions (nitrogen content and the presence or absence of biotin or autolysate in the medium).     

The metabolism of glucose by the rabbit lens in the presence and absence of oxygen

1. The effect of the absence of oxygen on the metabolism of [U-(14)C]glucose by the rabbit lens has been examined. 2. Protein-free extracts of incubated lens were subjected to electrophoresis followed by chromatography on paper; radioautographs showed 10 compounds substantially labelled. In the absence of oxygen, less radioactivity appeared in glucose, sorbitol, fructose, alanine, glutamic acid, glutathione and nucleotides, and more in lactic acid, alpha-glycerophosphate and glycerol. 3. The radioactivity of lens protein was about two to four times greater after aerobic than after anaerobic incubation. 4. The radioactivity of carbon dioxide was 2- to 4-fold greater after aerobic incubation than after anaerobic incubation. 5. After aerobic incubation of the lens, the radioactivity of all the labelled compounds was higher in the outer part (cortex) than in the inner part (nucleus). 6. Free glycerol has been found to be present in the lens. Its concentration, and that of alpha-glycerophosphate, has been measured in the lens of several species of animal.     

The catabolism of glucose in Tenebrio molitor: The effects of corpora cardiaca

During the development of the mealworm Tenebrio molitor, the effects of corpora cardiaca (CC) extracts on glucose catabolism were tested. In control insects and in insects receiving CC extracts, the activity of the pentose cycle and the glycolytic-citric acid cycle, were evaluated in vivo by a radiorespirometric method using [1-¹⁴C] glucose and [6-¹⁴C] glucose as substrates. The CC extracts strongly divert glucose from the pentose phosphate pathway, which is very active in Tenebrio molitor. Glucose oxidation is reduced by the CC extracts in pupae and adults but is increased in last instar larvae. It seems that the effects of CC extracts vary depending upon the state of carbohydrate reserves.     

Role of certain potato tubers constituents in their resistance to bacterial soft rot caused by Erwinia carotovora pv. carotovora

Erwinia soft rot causes destructive and serious damages to many vegetable crops including potato, in the field, transit and storage periods. The role of certain potato tuber constituents in the physiology of disease resistance has been investigated. Pectin substances and calcium contents of potato tuber had a pronounced role in the physiology of disease resistance. Alpha and Santa (less susceptible cultivars) contained the higher amount of pectin and calcium compared by Mirkal, Diamant, Askort, Geganite and Nicola cultivars (more susceptible cultivars). Tubers extracts of all healthy tested potato tubers cultivars contained fructose except Santa cultivar and glucose except Alpha and Mirkal cultivars. Tuber extracts of the more susceptible cultivars (Nicola and Askort) contained a higher concentration of glucose and fructose than those of less susceptible cultivars (Geganite, Mirkal, Santa, Alpha and Diamant).     

Enzymes of glucose metabolism in Frankia sp.

Enzymes of glucose metabolism were assayed in crude cell extracts of Frankia strains HFPArI3 and HFPCcI2 as well as in isolated vesicle clusters from Alnus rubra root nodules. Activities of the Embden-Meyerhof-Parnas pathway enzymes glucokinase, phosphofructokinase, and pyruvate kinase were found in Frankia strain HFPArI3 and glucokinase and pyruvate kinase were found in Frankia strain HFPCcI2 and in the vesicle clusters. An NADP+-linked glucose 6-phosphate dehydrogenase and an NAD-linked 6-phosphogluconate dehydrogenase were found in all of the extracts, although the role of these enzymes is unclear. No NADP+-linked 6-phosphogluconate dehydrogenase was found. Both dehydrogenases were inhibited by adenosine 5-triphosphate, and the apparent Km's for glucose 6-phosphate and 6-phosphogluconate were 6.86 X 10(-4) and 7.0 X 10(-5) M, respectively. In addition to the enzymes mentioned above, an NADP+-linked malic enzyme was detected in the pure cultures but not in the vesicle clusters. In contrast, however, the vesicle clusters had activity of an NAD-linked malic enzyme. The possibility that this enzyme resulted from contamination from plant mitochondria trapped in the vesicle clusters could not be discounted. None of the extracts showed activities of the Entner-Doudoroff enzymes or the gluconate metabolism enzymes gluconate dehydrogenase or gluconokinase. Propionate- versus trehalose-grown cultures of strain HFPArI3 showed similar activities of most enzymes except malic enzyme, which was higher in the cultures grown on the organic acid. Nitrogen-fixing cultures of strain HFPArI3 showed higher specific activities of glucose 6-phosphate and 6-phosphogluconate dehydrogenases and phosphofructokinase than ammonia-grown cultures.     

Repression of Pseudomonas putida phenanthrene-degrading activity by plant root extracts and exudates

The phenanthrene-degrading activity (PDA) of Pseudomonas putida ATCC 17484 was repressed after incubation with plant root extracts of oat (Avena sativa), osage orange (Maclura pomifera), hybrid willow (Salix alba x matsudana), kou (Cordia subcordata) and milo (Thespesia populnea) and plant root exudates of oat (Avena sativa) and hybrid poplar (Populus deltoides x nigra DN34). Total organic carbon content of root extracts ranged from 103 to 395 mg l(-1). Characterization of root extracts identified acetate (not detectable to 8.0 mg l(-1)), amino acids (1.7-17.3 mg l(-1)) and glucose (1.6-14.0 mg l(-1)), indicating a complex mixture of substrates. Repression was also observed after exposure to potential root-derived substrates, including organic acids, glucose (carbohydrate) and glutamate (amino acid). Carbon source regulation (e.g. catabolite repression) was apparently responsible for the observed repression of P. putida PDA by root extracts. However, we showed that P. putida grows on root extracts and exudates as sole carbon and energy sources. Enhanced growth on root products may compensate for partial repression, because larger microbial populations are conducive to faster degradation rates. This would explain the commonly reported increase in phenanthrene removal in the rhizosphere.     

Pyruvate Carboxylase Deficiency in Pleiotropic Carbohydrate-Negative Mutant Strains of Pseudomonas aeruginosa

Cell extracts of Pseudomonas aeruginosa strain PAO were found to contain pyruvate carboxylase activity. Specific activities were minimal when cells were grown on Casamino Acids, acetate, or succinate, but were three- to fourfold higher when cells were grown in glucose, gluconate, glycerol, lactate, or pyruvate minimal media. The reaction in crude cell extracts and in partially purified preparations was dependent on pyruvate, adenosine 5'-triphosphate, and Mg(2+), but was not affected by either the presence or absence of acetyl coenzyme A. Activity was nearly totally inhibited by avidin and this inhibition was substantially blocked by free biotin in incubation mixtures. Cell extracts were shown to fix (14)CO(2) in a reaction that had these same characteristics. Eight pleiotropic, carbohydrate-negative mutant strains of the organism were isolated after nitrosoguanidine mutagenesis. Each mutant strain grew normally in acetate, succinate, and citrate minimal media but failed to utilize glucose, gluconate, 2-ketogluconate, mannitol, glycerol, lactate, and pyruvate as sole sources of carbon and energy. These strains were found by quantitative transductional analysis with phage F116 to form a single linkage group. Cell extracts of each mutant strain were either lacking or severely deficient in pyruvate carboxylase activity. Spontaneous revertants of five of the eight strains were isolated and found to recover simultaneously both pyruvate carboxylase activity and the ability to utilize each of the C(6) and C(3) compounds. A second linkage group of similar mutant strains that grew on the C(3) compounds was found to contain normal levels of pyruvate carboxylase activity, but each strain was deficient in an enzyme of the Entner-Doudoroff pathway.     

In vitro glucose uptake activity of Aegles marmelos and Syzygium cumini by activation of Glut-4, PI3 kinase and PPARγ in L6 myotubes

The purpose of the present study is to investigate the effect of methanolic extracts of Aegles marmelos and Syzygium cumini on a battery of targets glucose transporter (Glut-4), peroxisome proliferator activator receptor gamma (PPARgamma) and phosphatidylinositol 3' kinase (PI3 kinase) involved in glucose transport. A. marmelos and S. cumini are anti-diabetic medicinal plants being used in Indian traditional medicine. Different solvent extracts extracted sequentially were analysed for glucose uptake activity at each step and methanol extracts were found to be significantly active at 100ng/ml dose comparable with insulin and rosiglitazone. Elevation of Glut-4, PPARgamma and PI3 kinase by A. marmelos and S. cumini in association with glucose transport supported the up-regulation of glucose uptake. The inhibitory effect of cycloheximide on A. marmelos- and S. cumini-mediated glucose uptake suggested that new protein synthesis is required for the elevated glucose transport. Current observation concludes that methanolic extracts of A. marmelos and S. cumini activate glucose transport in a PI3 kinase-dependent fashion.     

Studies on cyclic adenosine 3' ,5'-monophosphate levels, Adenylate cyclase and phosphodiesterase activities in the dimorphic fungus Mucor rouxii.

The germination of spores of Mucor rouxii into hyphae was inhibited by 2 mm dibutyryl cyclic adenosine 3′,5′-monophosphate or 7 mm cyclic adenosine 3′,5′-monophosphate; under these conditions spores developed into budding spherical cells instead of filaments, provided that glucose was present in the culture medium. Removal of the cyclic nucleotides resulted in the conversion of yeast cells into hyphae. Dibutyryl cyclic adenosine 3′,5′-monophosphate (2 mm) also inhibited the transformation of yeast to mycelia after exposure of yeast culture to air.Since in all living systems so far studied adenylate cyclase and cyclic adenosine 3′,5′-monophosphate phosphodiesterase are involved in maintaining the intracellular cyclic adenosine monophosphate level, the activity of both enzymes and the intracellular concentration of cyclic adenosine monophosphate were investigated in yeast and mycelium extracts. Cyclic adenosine monophosphate phosphodiesterase and adenylate cyclase activities could be demonstrated in extracts of M. rouxii. The specific activity of adenylate cyclase did not vary appreciably with the fungus morphology. On the contrary, cyclic adenosine monophosphate phosphodiesterase activity was four- to sixfold higher in mycelial extracts than in yeast extracts and reflected quite accurately the observed changes in intracellular cyclic adenosine monophosphate levels; these were three to four times higher in yeast cells than in mycelium.     

Application of NMR based metabolomics for mapping metabolite variation in European wheat

In this study, we report on the use of NMR-based metabolomics to access variation in low molecular weight polar metabolites between the European wheat cultivars Apache, Charger, Claire and Orvantis. Previous unassigned resonances in the published NMR spectra of wheat extracts were identified using ¹³C NMR and two dimensional proton-carbon NMR. These included a peak for trans-aconitate (δ3.43) and resonances corresponding to fructose in the crowded carbohydrate region of the spectra. Large metabolite differences were observed between two different growth stages, namely the coleoptile and two week old leaf tissue extracts which were consistent across cultivars. Two week old leaf tissue extracts had higher abundances of glutamine, glutamate, sucrose and trans-aconitate and less glucose and fructose than were observed in the coleoptile extracts. Across both growth stages the cultivars Apache and Charger showed the greatest differences in metabolite profiles. Charger had higher abundances of betaine, the single most influential metabolite in the principal component analysis, in addition to fructose and sucrose. However, Charger had lower levels of aspartate, choline and glucose than Apache. These findings demonstrate the potential for a biochemical mapping approach using NMR, across European wheat germplasm, for metabolites of known importance to functional characteristics.     

Comparison of acetate and glucose incorporation into rat and horse skin lipids

The relative efficiency of acetate and glucose as substrates for the biosynthesis of lipids in the skin of the rat and horse was examined using in vivo pulse labelling of skin with [1-14C]acetate and [U-14C]glucose by intradermal injections. The resulting radiolabelled lipids were recovered in the rat by punch biopsy as well as by daily, long-term skin surface lipid collections and in the horse by punch biopsy of the injection sites. The lipids were examined by liquid scintillation and by a combination of thin-layer chromatography and autoradiography. In both species the recovery of radiolabel in the non-polar lipids was much higher after a pulse of [1-14C]acetate than after a pulse of [U-14C]glucose. In the rat, the skin surface lipids labelled through acetate contained sufficient radiolabel to allow observation of the time course of excretion of 14C in the major non-polar lipid classes. The results suggest that the biosynthesis of these lipid classes in the sebaceous glands of the rat are not entirely synchronous. In the skin lipid extracts of the horse, all of the major lipid classes, including phospholipids and glycolipids, were labelled through acetate. In contrast, none of the non-polar lipids and very little of the polar lipids were labelled through glucose.     

Fermentation effects of oligosaccharides of Radix Ophiopogonis on alloxan-induced diabetes in mice

In this study, oligosaccharides extracted from Ophiopogon japonicus vinegar (OOV) by alcoholic and acetic acid fermentation with water extracts from Radix Ophiopogon and oligosaccharides extracted from Radix Ophiopogonis (OOJ) were investigated. Characterization of the extracts indicated that OOV are proteoglycans, whereas OOJ are not. Moreover, compared with OOJ, monosaccharide compositions of OOV only include fructose and galactose and not glucose. MALDI-TOF-mass spectrometric results showed that the molecular weight of OOV was smaller after fermentation. Changes in the characteristics of OOV would inevitably lead to changes in its hypoglycemic properties. The OOV inhibition activity against α-glucosidase was stronger than that of OOJ. The inhibition activity became stronger with higher dosages of OOV. The hypoglycemic effect of OOV on alloxan-induced diabetic mice was stronger than that of OOJ. More important, the ability of OOV to reduce damage on islets in diabetic mice was stronger than that of OOJ. Overall, alcoholic and acetic acid fermentation improved the hypoglycemic activity of OOJ.     

Reduction of trimethylamine N-oxide by Escherichia coli as anaerobic respiration.

E. coli was found to grow anaerobically on lactate in the presence of trimethylamine N-oxide (TMANO), reducing it to trimethylamine. Anaerobic growth on glucose was promoted in the presence of TMANO. When a culture grown in complex medium was transferred to defined medium, growth on glucose and ammonia took place in the presence of TMANO after consumption of complex nutrients introduced with the preculture, in contrast to growth in nitrate respiration. The amounts of ethanol, succinate, and lactate among the fermentation products were decreased and that of acetate was increased in the presence of TMANO. Formate generation was much reduced at pH 7.4, whereas stoichiometric formation of formate was observed in the absence of TMANO. Cells grown anaerobically in the presence of TMANO had a higher activity of amine N-oxide reductase than cells grown under other conditions. The content of cytochrome-558 was elevated in the presence of TMANO during growth in complex medium. Cytochrome c-552 found in cells grown in diluted complex medium or defined medium in the presence of TMANO was oxidized by TMANO in cell extracts. The molar growth yield on glucose was higher in the presence of TMANO than in its absence and lower than that in the presence of nitrate.     

Hepatic mechanisms of the Walnut antidiabetic effect in mice

The present study was designed to explore the mechanism of action of walnut (the seed of Juglans regia) leaf and ridge on hepatic glucose metabolism in diabetic mice. Experimental diabetes was induced by intravenous administration of streptozotocin (60 mg/kg)and confirmed with an increase of blood glucose, 90–100% of the control, 72 hours later. Isolated extracts from walnut leaf and ridges were administered in a single effective dose of 400 mg/kg orally. Firstly, blood glucose was determined every 1 hour until 5 hours post administration of extracts. In the second experiment, the liver was surgically removed, 2 hours post treatment of diabetic animals with extracts, homogenized and used for measurement of key enzymes of glycogenolysis (glycogen phosphorylase, GP) and gluconeogenesis (phosphoenolpyruvate carboxykinase, PEPCK). Treatment by both leaf and ridge extracts decreased blood glucose and liver PEPCK activity and increased blood insulin and liver GP activity. It is concluded that walnut is able to lower blood glucose through inhibition of hepatic gluconeogenesis and secretion of pancreatic insulin.     

Mechanisms of Protection of Trehalase Against Heat Inactivation in Neurospora

The half-life of trehalase and invertase at 65 and 60 C was found to be much greater when intact ascospores of Neurospora tetrasperma were heated, as compared with extracts. By contrast, no protection was afforded these enzymes when they were heated in intact conidia and mycelium of N. crassa or N. tetrasperma. The protective effect of ascospores for trehalase was further investigated by heating ascospore extracts before and after dialysis. The removal of small molecules by dialysis lowered the heat resistance of trehalase significantly in such extracts. When the dialysate from extracts of mycelium, conidia, or ascospores was added to dialyzed enzyme extracts, that from ascospores was by far the most active. However, the same dialysates had only a small protective effect on invertase. The addition of ashed dialysates did not protect trehalase, and trehalose and glucose protected less effectively than the dialysate.